High-energy hadron spin-flip amplitude at small momentum transfer and new A N data from RHIC
Institut de Physique, Université de Liége, Bât. B5a, B-4000, Sart Tilman, Liége, Belgium
2 Dipartimento di Fisica Teorica, Universitá di Torino and Sezione INFN di Torino, Torino, Italy
* e-mail: J.R.Cudell@ulg.ac.be
In the case of elastic high-energy hadron-hadron scattering, the impact of the large-distance contributions on the behaviour of the slopes of the spin-non-flip and of the spin-flip amplitudes is analysed. It is shown that the long tail of the hadronic potential in impact parameter space leads to a value of the slope of the reduced spin-flip amplitude larger than that of the spin-non-flip amplitude. This effect is taken into account in the calculation of the analysing power in proton-nucleus reactions at high energies. It is shown that the preliminary measurement of A N for p 12C obtained by the E950 Collaboration indeed favours a spin-flip amplitude with a large slope. Predictions for A N at GeV/c are given.
© Società Italiana di Fisica and Springer-Verlag, 2004